Tubular frame-joint



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m Ym RJ BE PM M HP m Tm U T a d o M 0 m Patented Mar. 9, 1897.

(No Model.) 2 Sheets-Sheet 2. I

T. JEFFERY.

TUBULAR FRAME JOINT.

No. 578,403. Patented Mar. 9, 1897.

THE RONNIE PETERS CO. FNQYDAIYNOP WASHINEYON, D C I V UNITED I STATES PATENT FFICE.

THOMAS E. JEFFERY, OF CHICAGO, ILLINOIS.

TUBULAR FRAME-JOINT.

SPECIFICATION forming part of Letters Patent No. 578,403, dated March 9, 1897. Application filed November 11,1895. Serial No 568,520,- (No model.)

To all whom it may concern.-

Be it known that I, THOMAS B. JEFFERY, a citizen of the United States, residing at Chicago, county of Cook, and State of Illinois,

5 have invented certain new and useful Improvements in Tubular Frame-Joints, which are fully se tforth in the following specification, reference being had to the accompanying drawings, forming a part thereof.

This invention relates to a joint in a tubular frame, such as occurs at the crank-axle bearing of a bicycle of the most familiar type, the frame at that point comprising two tubular arms which diverge upwardly, one to the steering-head and the other to the seat-support, and the tubular cross-head at right angles to the plane of the two diverging tubular arms, said cross-head being the support for the crank-axle bearing. This joint in a bicycle-frame requiring great stiffness has customarily been made from a solid casting or forging, which has been bored out through the cross-head and through the two diverging arms into the cross-head in order to suitably lighten the fitting and adapt it to have the tubular arms of the frame secured to the diverging sockets of the fitting. Such structure cannot be made so light consistently with the required strength as a fitting made out of sheet or plate metal suitably formed with dies for the purpose.

My present invention consists in a novel formation of such joint from sheet metal, as particularly set out in the claims.

Figure 1 is aside elevation of myimproved joint. Fig. 2 is a perspective of the larger of the parts of this frame-joint. Fig. 3 is a perspective of the smaller part. Figs. 4 and 5 are plans of the blanks from which the two parts are formed, respectively. Figs. 6 and 7 are perspectives of the same parts, respectively, after one step in the process of shaping them with dies has been performed.

My improved joint is made of two pieces originally. The part A, comprising more than half of the entire-circumferential extent of the cylindrical cross-head, as seen at A, and

' the outer halves A and A substantially of both the diverging arms, is formed from a blank cut from sheet metal, and represented in Fig. 4, suitable dies being employed first to reduce the blank to substantially the form shown in Fig. 6 and afterward to complete the folding up of the cross-head into proper cylindrical form, as seen in Fig. 2. The edges of the portion A of the cross-head and the edges of the portions A and A of the diverging arms, respectively, are chamfered off at a, a and a on the outer side, as seen in Fig. 2, to receive the lap of the corresponding edges of the part B, which comprises the smaller remainder B of the cylindrical crosshead and the innerhalves l3 and B of the diverging arms, respectively.. The edges of the portion B of the cross-head and the portion B and B of the tubular arms are chamfered off at 1), b and 29 respectively, on the inner side, as seen in Fig. 3, to adapt them to lap on it the exterior chamfered corresponding edges of the part A, when the two parts are complete, one to the other to complete the fitting, which is done by brazing together the chamfered and lapped edges of the crosshead and its arms, respectively.

The diverging arms of the fitting are preferably, as shown, cut away in a taper from the diametrical plane at which the two parts A and B are united, so that in the complete fitting said arms constitute sockets which terminate in tapering fingers'whose points are all substantially in the plane of the axes of the two diverging arms of the frame,which are to be secured in said sockets and on opposite sides of the said arms, respectively. The object of this formation is to properly distribute the strain and prevent a breaking strain on the tubular arms.

1. A tubular framejoint comprising a tubular cross-head and two tubular arms or sockets diverging from each other in a plane transverse to the cross-head said joint being made from two pieces of sheet metal, one of which comprises the portion of the entire fitting which is defined between two planes which contain the axis of the cross-head and 1 the axes of the arms respectively; and the other of which comprises the remainder of said fitting; one of said parts having the edges adjacent to said planes extended circumferential with respect to said cross-head and arms respectively to afford surface for lap and junction with the other part; substantially as set forth.

2. A tubular frame-joint comprising a tubular cross-head and two tubular arms or sockets diverging from each other in a plane transverse to the cross-head; said joint being made from two pieces of sheet metal, one of which comprises the portion of the entire fitting which is defined between two planes which contain the axis of the cross-head and the axes of the arms respectively; and the other of which comprises the remainder of said fitting; one of said parts having the edges adjacent to said planes extended and chamfered upon one surface, and the other part having the corresponding edges chamfered upon the opposite surface; substantially as set forth.

3. A tubular frame-joint comprising a tubular crosshead and two tubular arms or sockets diverging from each other in a plane THOS. B. JEFFERY.

\rVitnesses:

GEO. E. Swmsoon, J. J. YOUNG. 

